supporting science, technology, and improved economic performance and financial literacy in the 21st century. >> and with the ongoing support of these institutions and foundations. and... >> this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> brown: the chechen-american teenager accused in the boston marathon bombings now faces a possible death sentence. the filing of charges today officially moved the case into the federal courts, even as the city began returning to normal. dzhokhar tsarnaev was arraigned this morning, at boston's beth israel deaconess hospital, where he remained in serious condition. a short time later came word of the complaint, filed by the u.s. justice department. it formally charged the 19-year- old with conspiring to use a weapon of mass destruction, potentially, a capital crime, punishable by the death penalty. and, destruction of property by explosive device, causing death. tsarnaev had been able, sporadically, to answer questions in writing, but a gunshot wo